Sampling programs are often conducted in the oil field to reduce risk. For example, down hole sampling during the formation evaluation stage of field development can be used to provide representative subsurface formation fluids for analysis. The purpose of the analysis includes determination of bulk fluid properties and phase behavior, as well as geochemistry, flow assurance, assay for oil valuation, compatibility studies, and reservoir compartmentalization and continuity studies. The resulting data can be used to book reserves, and to design production strategies, enhanced oil recovery strategies, and surface handling facilities, et cetera.
Depending on the purpose of the sampling, it may be useful to obtain a variety of sizes and numbers of samples. Often only one bulk fluid sample is required from a reservoir section, with other sections having a largely reduced requirement. For example, pressure-volume-temperature (PVT) work may require only 200 mL in a sample to produce useful results. For analytical work, only 40 mL may be needed. In some cases, even these quantities are sufficient for multiple, repeated analyses because advanced analysis techniques can provide complete geochemistry fluid characterization with as little as one mL of fluid volume.